PYROCON12 power modulator: zones do not run in Manual ON

Check manual duration, zone sequencing, enabled outputs and sensor faults.

For the PYROCON12 revision 5.2.5 controller, Manual ON requests heating without waiting for a snow-detection signal. Use these checks before replacing a sensor or controller:

1. Press SELECT until Manual ON is selected. A power-off/power-on cycle returns the control to Automatic.
2. Check the P05 manual-run duration and whether it has expired.
3. Check the zone indicators, enabled zones and sequencing settings. The system can stagger its outputs, so not every zone is expected to be on at once.
4. Have the installer review the temperature limits and their actual sensor readings against the required installation settings.
5. Record any SensErr message. SensErr 1 indicates a snow-sensor communication fault. SensErr 2 indicates a disconnected or shorted upper-limit sensor.

For SensErr 2, the manual states that the system continues without the upper-temperature limit. Turn the system off and have the fault corrected before relying on that protection. Do not disconnect a sensor or disable the limit as a routine homeowner test.

If the control calls for heat but a zone stays cold, a qualified electrician should check that zone’s power, contactor, protection and heating circuit. The symptom alone does not prove that the aerial sensor failed.

Source: PYROCON12 revision 5.2.5 manual (pages 6–9 and 13–14).